This invention relates to thermally actuated machines which pump heat, without the intermediary conversion to shaft power, by employing freely oscillating positive displacement elements that subject working fluids to a thermodynamic cycle.
In energy conversion, it is often necessary to convert heat energy to pump heat for achieving a desirable temperature. It is further desirable to convert energy at as high an efficiency as possible, limited only by the First and Second Laws of Thermodynamics. It is further desirable that this be done by machines that are simple, compact, quiet and reliable and that are self-starting and self-regulating to load variations. The present invention meets these requirements and can be varied in configuration and function to match a wide range of output and performance requirements.
Broadly stated, the present invention relates to machines in which freely oscillating positive displacement mechanical elements periodically subject a working fluid to a thermodynamic cycle through continuous thermal energy interchange with the surroundings and thereby produce a net heating or cooling effect (heat pumping) without intermediary conversion to shaft work. The continuous thermal energy interchange (as opposed to the intermittent thermal energy interchange produced in spark or compression ignited combustion engines), casued by a temperature difference between a thermal source and sink, provides the driving potential through volume and pressure change (related by the equation of state of the working fluid) to produce the driving force for the oscillation of the positive displacement elements. As a result, whenever a temperature difference is impressed on this thermal machine, heat is pumped from a lower to a higher temperature thereby producing a cooling effect at the lower temperature and a heating effect at the higher temperature.